The following description relates to waterproof covers and, more specifically, to a waterproof cover for an electrical cabinet that meets NEMA4 standard requirements.
The National Electrical Manufacturers Association (NEMA) is a US manufacturing organization which actively promotes standardized product specifications for electrical apparatuses. While NEMA does not actually test products, it establishes the performance criteria for enclosures intended for specific environments. NEMA standards describe each type of enclosure in general and functional terms and specifically omits reference to construction details. In other words, NEMA specifies what an enclosure must do, not how to manufacture it. As an example, NEMA4 enclosures are used in many applications where an occasional washdown occurs or where machine tool cutter coolant is used. They also serve in applications where a pressurized stream of water will be used. NEMA4 enclosures are gasketed and the door is clamped for maximum sealing.
Electrical cabinets might be able to meet certain requirements but cannot NEMA4 satisfy NEA4 requirements if they are unable to prevent water ingress from spraying. This is particularly true for covers of IP55 fan filters. The covers often lack lower filtering assemblies and thus allow for the ingress of water that is sprayed onto the covers.